And CS could still be divided into color themes like grey/blue, white/blue, gray, blue.

That brings me also to my latest uploads on flickr, where I posted a quartet space card game. I named it "Space-Sets der Moderne" which means "modern space-sets" or "space sets of the modern". That was my term to cover the space themes after CS. look here.

Then there's the rest, which is good but different somehow: Unitron, Spyrius, UFO, Insectoids, Exploriens, Roboforce

Of course this is just my opinion.

I like the way that BobaFett2 set out these generational groups and agree with his idea of "classic space" parameters as well as Stargorger's and mdilthey's parameters, if your talking about sets. If on the other hand you're talking about MOCs then it gets more complicated and I would group a lot of MOCs (and the new Space Police III) into a Neo-Space/Neo-Classic Space or just Space theme that largely differentiated from the older themes by the use of generally sleeker/more curved shapes.Mars and Star Wars could be grouped with these MOCs, but neither of these feel like a Lego Theme the way Space Police III does. For Star Wars it's obviously because it's a franchise, and Mars for kinda' the same reason, I seem to recall there being a probe landing on mars right bout the time the first Mars line came out(?) which makes it feel like a NASA franchise to me.EDIT: I may have diverged from the topic at hand. I'm curious why fibblesnork doesn't have anything after 1997, it looks like a good resource for themes and the rest of lugnet seems to be alive and well...